We request funding for a biennial "Workshop on the Nuclear Radiology of Breast Cancer". This proposed workshop immediately follows the annual IEEE Nuclear Science Symposium & Medical Imaging Conference in years 2004, 2006, and 2008. In 2002 a similar Workshop was co-funded by NCI and NIBIB. As in 2002 the overall goals of the proposed events are to convene imaging physicists and engineers as well as chemists, biologists, physicians and students from around the world to discuss important issues related to breast cancer evaluation using functional imaging techniques involving nuclear radiotracers. Key issues to address are the recent successes and limitations of nuclear imaging approaches [positron emission tomography (PET) and single photon emission computed tomography (SPECT)] and what steps are required to continue to increase their role in breast cancer management. Thus in addition to having educational goals the meeting serves as a venue to understand and perhaps suggest solutions to important problems associated with breast cancer detection, diagnosis, and staging. The outline of the two-day program is as follows: (1) Review of the biology, biochemistry, and markers of breast cancer; (2) Review of the clinical state-of-the-art in breast cancer radiology using standard approaches; (3) Overview of promising new technologies for breast cancer imaging; (4) Review of current clinical perspectives on the role of nuclear medicine breast imaging; (5) Discussion of the cost-effectiveness of nuclear breast imaging; (6) Overview of breast cancer treatment and role of nuclear medicine in chemo-resistance determination; (7) Review of existing and promising breast cancer radiotracers; (8) Clinical trial results with commercial dedicated nuclear emission cameras; (9) International review of research groups specifically working on improving gamma ray and positron emission cameras dedicated to breast cancer imaging; (7) International commercialization and long term industrial outlook of dedicated breast imaging modalities; and (8) Research funding opportunities. While there is a logically progressive and structured format, the setting is meant to be informal, with a larger portion of the workshop devoted to discussion and interaction between the audience members and presenters compared to standard didactic scientific meetings. To encourage an intimate environment for information exchange and problem solving the workshop will be limited to 100 participants with strong interest in this field. Two members per research group will be invited to participate. There will be appropriate involvement of women and minorities. There will also be a competition for up to 10 student travel awards to promote education/training in this field. This workshop will provide the latest research information and lively interaction and discussions. The resulting information will be made available to the public.